MANILA - The Philippines' largest hospital chain has filed for an IPO, it said in a filing on Wednesday, even as bidders are reportedly lining up to buy a 40% stake in the business from its parent Metro Pacific Investments Corp.

In a filing to the Securities and Exchange Commission, Metro Pacific Hospitals Holdings Inc said it plans to sell as much as 457.86 million shares, including over-allotment option, at a maximum price of 182 pesos ($3.47) per share.

At that price, the hospital group could raise as much as 83.33 billion pesos ($1.6 billion), but price ceilings cited in Philippine IPO filings are tentative.

San Miguel, the country's best known conglomerate, raised only $634 million in a share sale last year, versus its initial indicative target of up to $2.7 billion.

Metro Pacific Investments currently has an 85.6% stake in Metro Pacific Hospitals, while Singapore sovereign wealth fund GIC owns the rest of the unit.

Buyout firms KKR, Blackstone BX.N and CVC are among bidders competing for a stake in the hospital unit, people with knowledge of the matter have told Reuters. 

Under the IPO plan, four-fifths of the shares for sale would come from Metro Pacific Investments, which also has interests in power, water and toll roads.

Metro Pacific Hospitals operates 14 hospitals, many of which are among the Philippines' largest and most modern. It targets to operate a network of 5,000 beds in the next few years from the current 3,200 beds by acquiring smaller hospitals.

"This would be huge for the business and the capital expenditures needed for our hospitals' continued expansion," David Nicol, CFO of Metro Pacific Investments, told Reuters.

The healthcare chain has hired UBS UBSG.S , Bank of America Merrill Lynch, CLSA, and JPMorgan, among others, to arrange the IPO, which is set in November. ($1 = 52.4500 Philippine pesos)

(Reporting by Neil Jerome Morales; Editing by Himani Sarkar) ((neiljerome.morales@thomsonreuters.com; +632 8418914;))